1. Field of the Invention
This invention relates to improved performance apertures and mirrors for Vertical-Cavity Surface-Emitting Lasers (VCSELs).
2. Description of the Related Art
(Note: This application references a number of different publications as indicated throughout the specification by one or more reference numbers within brackets, e.g., [x]. A list of these different publications ordered according to these reference numbers can be found below in the section entitled “References.” Each of these publications is incorporated by reference herein.)
VCSELs show promise for use in future optical interconnects because they can achieve higher data rates with less power dissipation. Most of the high-speed VCSELs have larger dimensions, 5-7 μm in diameter, and require higher current to achieve high bandwidth.
Oxide apertures within the VCSEL have been used to minimize power dissipation by constricting current within the lasing modes and guiding laser modes (thereby increasing overlap between carriers and optical modes and reducing sidewall losses) [1,2]. However, in the prior art these apertures have produced undesirable optical scattering due to their imperfect shape [1,2], and a larger mode diameter is needed for low optical loss. The present invention aims to reduce or eliminate this parasitic effect by using properly engineered apertures to enable smaller mode diameters (<5 μm) for increased modulation bandwidth with lower power dissipation. Because of the reduced optical scattering loss at smaller device diameters, the present invention enables both lower parasitic capacitance as well as higher intrinsic modulation bandwidth at lower power dissipation.